Roadless Areas
Home/Species/ Bradley's Spleenwort

Asplenium bradleyi

D.C. Eat.

Bradley's Spleenwort

G4Apparently Secure Found in 2 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
Identity
Unique IDELEMENT_GLOBAL.2.129065
Element CodePPASP02050
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumFilicinophyta
ClassFilicopsida
OrderFilicales
FamilyAspleniaceae
GenusAsplenium
Other Common Names
Bradley's spleenwort (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
FNA (1993, vol. 2), Kartesz (1994), and Weakley and the Southeastern Flora Team (2024) accept Asplenium bradleyi. The generic placement of this taxon is in accordance with the Pteridophyte Phylogeny Group I (2016).
Conservation Status
Rank MethodLegacy Rank calculation - Excel v3.1x
Review Date1993-05-31
Change Date1993-05-31
Edition Date2018-01-25
Edition AuthorsOstlie, W. R. (MRO), rev. Treher (2018)
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Widespread species with localized distribution. Some parts of the range have greater threats than others, for example, some areas in the Appalachian Mountains are threatened by strip mining activities. This species is more common than occurrence records indicate in some parts of the species range.
Range Extent Comments
Asplenium bradleyi has a very spotty distribution over much of its range which includes the Appalachians and Ozark regions (Werth pers. comm.). The species occurs from southern New York and New Jersey to Georgia and Alabama, west to Ohio, Missouri and Oklahoma (Gleason and Cronquist 1963).
Occurrences Comments
"Occurring rarely to locally in the Appalachian region... but it is fairly frequent in the Ozark and Ouachita region... (FNA 1993)"
Threat Impact Comments
One of the primary threats to A. bradleyi is the destruction of habitat through strip-mining activities (Werth pers. comm.). Within portions of the Appalachians, coal underlies the sandstone strata on which A. bradleyi grows. These activities are a significant threat in the Cumberland Plateau region of Kentucky and Tennessee.

Additional threats include the logging of upland forests above the cliff in such a way that slash is left against the cliff face (Ortt pers. comm.). Logging of adjacent forests may also be a threat due to changes in light levels and the consequent onset of desiccation brought about by such activities (Evans pers. comm.).

Rock climbers are another potential threat to existing populations (Ortt pers. comm., Schwegman pers. comm.). At one site in Ohio, climbers nearly destroyed a population. Fortunately, some plants survived in areas that were not accessed by the climbers (Ortt pers. comm.).

A population growing along a township road has been extirpated since the re-opening of the road roughly ten years ago (1980). It is unknown whether the population succumbed from physical damage by road work, change in air quality (dust/fumes) or some other subtle factor (Ortt pers. comm.).

Some plants have been killed by extreme drought conditions which deplete moisture within the rocks (Schwegman pers. comm.). Since A. bradleyi is a species typically found in habitats prone to severe drought, these events do not likely make a lasting impact on natural populations.
Ecology & Habitat

Description

This is a small, tightly packed fern that grows upright from the cracks in cliff faces and rocks. The leaves are 4-20 cm long and divided once into 6-14 pairs of triangular leaflets that have toothed edges. The lowest pair are the largest and the leaflets very gradually diminish in size toward the tip of the leaf. The lower half of the leaf stalk is black and shiny and the upper half is green.

Habitat

Habitat includes the crevices of sandstone cliffs and ledges where other vegetation is typically lacking (Werth pers. comm.). The crevices in which the species occurs are typically large enough for A. bradleyi but too small for other larger fern species and flowering plants (Werth pers. comm.).

In Ohio, Asplenium bradleyi occurs in crevices on upper slopes of west to south facing sandstone outcrops (Ortt pers. comm.). Although this habitat type is plentiful within the state, occurrences of the species are few. Asplenium bradleyi grows on vertical or horizontal crevices but does not dwell on the ledges. Associates include Asplenium pinnatifidum, A. platyneuron and a few lichens.

In Missouri, A. bradleyi is scattered across 17 (mainly Ozarkian) counties, occurring on sandstone, granitic or chert bluffs in sheltered, dry, shaded crevices (Smith pers. comm.). Associates include some mosses adapted to dry sandstone. There is very little competition from other vascular plants.

Populations of A. bradleyi in Kentucky are known from dry, but mostly shaded sandstone cliffs (Evans pers. comm.). At times, A. montanum and A. pinnatifidum may occur nearby and may be considered associates.

In Illinois, A. bradleyi is found in crevices of sandstone cliff faces and cherty inclusions within limestone outcrops (Schwegman pers. comm.). Few other species grow in this harsh environment. Asplenium pinnatifidum is one of its few associates.

There are no known extant populations remaining in New York (Young pers. comm.). Two historic populations were known from the state, in the Shawangunk Mountains and the vicinity of Newburgh (NY NHP 1990).

Reproduction

Asplenium bradleyi is a highly-variable allotetraploid species (Werth pers. comm.). Its putative parents are the wide-ranging A. platyneuron, and A. montanum, a species nearly restricted to the Appalachians (Werth et al. 1985). Hybridization has occurred several times in the history of this taxon, creating an impressive genotypic array (Werth pers. comm., Werth et al. 1985). For additional information pertaining to the allotetraploid origins of A. bradleyi, see Werth et al. (1985).
Terrestrial Habitats
Sand/duneBare rock/talus/screeCliff
Other Nations (1)
United StatesN4
ProvinceRankNative
South CarolinaS1Yes
IndianaS1Yes
ArkansasSNRYes
West VirginiaS1Yes
KentuckyS3Yes
North CarolinaS2Yes
AlabamaS2Yes
New YorkS1Yes
New JerseyS1Yes
IllinoisS1Yes
PennsylvaniaS1Yes
VirginiaS2Yes
GeorgiaS2Yes
MissouriSUYes
MarylandS1Yes
OhioS1Yes
TennesseeS2Yes
OklahomaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
3 - Energy production & miningRestricted (11-30%)Unknown—
4 - Transportation & service corridorsUnknownUnknownUnknown
4.1 - Roads & railroadsUnknownUnknownUnknown
5 - Biological resource useUnknownUnknownHigh (continuing)
5.3 - Logging & wood harvestingUnknownUnknownHigh (continuing)
6 - Human intrusions & disturbanceUnknownUnknownHigh (continuing)
6.1 - Recreational activitiesUnknownUnknownHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.2 - DroughtsPervasive (71-100%)UnknownHigh (continuing)

—

Plant Characteristics
Economic Value (Genus)No
Roadless Areas (2)
Arkansas (1)
AreaForestAcres
Devils CanyonOzark-St. Francis National Forest1,877
Kentucky (1)
AreaForestAcres
WolfpenDaniel Boone National Forest2,835
References (15)
  1. Dodds, J. 2022. <i>Asplenium bradleyi</i> Rare Plant Profile. New Jersey Department of Environmental Protection, State Parks, Forests and Historic Sites, State Forest Fire Service and Forestry, Office of Natural Lands Management, New Jersey Natural Heritage Program, Trenton, NJ. 17 pp. [https://nj.gov/dep/parksandforests/natural/heritage/docs/asplenium-bradleyi-bradleys-spleenwort.pdf]
  2. Evans, M. 1990. Botanist/Field Representative, Kentucky Nature Preserves Commission. Personal communication: ESA questionnaire for Asplenium bradleyi. 4 pp.
  3. Flora of North America Editorial Committee (FNA). 1993a. Flora of North America north of Mexico. Vol. 2. Pteridophytes and gymnosperms. Oxford Univ. Press, New York. xvi + 475 pp.
  4. Gleason, H.A., and A. Cronquist. 1963. Manual of vascular plants of northeastern United States and adjacent Canada. D. Van Nostrand Company, New York, NY. 810 pp.
  5. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  6. New York Natural Heritage Program (NY NHP). 1990. Database records for <i>Asplenium bradleyi</i>. 4 pp.
  7. Ortt, M. 1990. Botanist, Ohio Department of Natural Resources. Personal communication: ESA questionnaire for Asplenium bradleyi. 4 pp.
  8. Pteridophyte Phylogeny Group I. 2016. A Community-Derived Classification for Extant Lycophytes and Ferns. Journal of Systematics and Evolution 54(6): 563–603.
  9. Schwegman, J. 1990. Botany Program Manager, Illinois Department of Conservation. Personal communication: ESA questionnaire for Aspemium bradleyi. 4 pp.
  10. Smith, T. E. 1990. Botanist, Missouri Department of Conservation. Personal communication: ESA questionnaire for Asplemium bradleyi.
  11. Watson, L. 1990. Coordinator/Botanist, Oklahoma Natural Heritage Inventory. Personall communication: ESA qustionnaire for Asplenium bradleyi. 4 pp.
  12. Weakley, A.S., and Southeastern Flora Team. 2024. Flora of the southeastern United States. Edition of March 4, 2024. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2203 pp.
  13. Werth, C. 1990. Professor of Biology, Texas Tech University. Personal communication with Wayne Ostile, MRO, The Nature Conservancy.
  14. Werth, C.R., S.I. Guttman, and W.H. Eshbaugh. 1985a. Recurring origins of allopolyploid species in <i>Asplenium</i>. Science 228: 731-733.
  15. Young, S. 1990a. Botanist, New York Natural Heritage Program. Personal commmunication: ESA questionnaire for <i>Arabis missouriensis</i> var. <i>deamii</i>. 4 pp.